Rails Lighthouse ticket #6406

xml_serializer.patch

diff --git a/activerecord/lib/active_record/serializers/xml_serializer.rb b/activerecord/lib/active_record/serializers/xml_serializer.rb
index 9bf1193..ae6f15a 100644
--- a/activerecord/lib/active_record/serializers/xml_serializer.rb
+++ b/activerecord/lib/active_record/serializers/xml_serializer.rb
@@ -252,7 +252,9 @@ module ActiveRecord #:nodoc:
         end
       else
         if record = @record.send(association)
-          record.to_xml(opts.merge(:root => association))
+          association_name = association.to_s.singularize
+          record_class = (record.class.to_s.underscore == association_name) ? nil : record.class.name
+          record.to_xml(opts.merge(:root => association, :type => record_class))
         end
       end
     end